This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in...This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertilization and improved farming practices that could be exploited for increased productivity of maize.展开更多
[Objectives]To find out a suitable cultivation technique of Wangu 098 in Nanyang area,speed up the popularization,demonstration and application of Wangu 098,and provide a theoretical and practical basis for adjusting ...[Objectives]To find out a suitable cultivation technique of Wangu 098 in Nanyang area,speed up the popularization,demonstration and application of Wangu 098,and provide a theoretical and practical basis for adjusting the planting structure and realizing the matching of improved varieties and methods.[Methods]The new self-bred millet variety Wangu 098 was used as the material,and the two-factor split zone experimental design was adopted.The effects of different sowing dates and densities on the yield,growth period and agronomic characters of millet were studied.[Results]The interaction of seeding date and density had a great effect on the yield and plant traits of millet.Millet yield was significantly and positively correlated with plant height,panicle length,single panicle weight,panicle grain weight and tiller number.[Conclusions]The reasonable combination of seeding date and density could give full play to the yield potential of millet.According to the experimental results and cultivation experience,the suitable seeding date of millet in Nanyang area is in the first and middle ten days of June,and the best density is about 750000 plants/ha.However,after June 30,the seeding millet did not tiller,so the density should be increased to more than 900000 plants/ha to obtain higher yield.In terms of cultivation and management,timely seeding,reasonable close planting,and coordination of vegetative growth and reproductive growth can make the plant tall and strong,panicle long and thick,and improve the yield of millet.展开更多
[Objectives]Sugarcane is the most significant sugar cash crop in the tropical and subtropical regions of China.However,it is notable for its narrow genetic basis,limited trait improvement,weak adaptability of varietie...[Objectives]Sugarcane is the most significant sugar cash crop in the tropical and subtropical regions of China.However,it is notable for its narrow genetic basis,limited trait improvement,weak adaptability of varieties,and poor planting efficiency.In order to accelerate the process of sugarcane variety replacement and expand the basis of genetic variation,interspecific hybridization and multiple mutagenesis are the most effective methods for obtaining new sugarcane varieties.The evaluation and identification of phenotypic traits of germplasm represents a significant analytical method.The"Zhongtang"series of sugarcane varieties is distinguished by its high yield and high sugar content.New sugarcane germplasms with excellent agronomic and quality traits can be identified and developed as breeding parents and new breeding lines through comprehensive evaluation of the existing germplasm.[Methods]A total of 181 new lines were selected through genetic origin and orientation,and evaluated and appraised for growth,yield,and economic characteristics.The data on 6 important agronomic and quality traits,including tillering,initial plant height,plant height,stem diameter,number of effective stems,and brix at maturity,were used to discover superior lines.These traits were evaluated during the two production seasons of the participant lines.[Results]A comprehensive evaluation of seedling growth traits and economic traits at maturity of the experimental lines identified 30 excellent new germplasms of sugarcane.Among the selected lines,1501 and 1701 exhibited superior agronomic and quality traits,rendering them suitable as parental lines for sugarcane breeding or breeding as new varieties.[Conclusions]The exemplary results obtained in this study provide a solid foundation for the improvement of sugarcane germplasm,with the goal of enhancing quality and efficiency.These findings are of great scientific and practical significance to the study of sugarcane yield and sugar-related genes,as well as the exploration of the evaluation and utilization of sugarcane germplasm resources.展开更多
When contributing to participatory research, farmers usually appreciate the performance of cowpea varieties using qualitative scores. The score they attribute to each variety are based on local knowledge. The specific...When contributing to participatory research, farmers usually appreciate the performance of cowpea varieties using qualitative scores. The score they attribute to each variety are based on local knowledge. The specific criteria they individually use to attribute a score are not well described. The objectives of this work were to: 1) identify and describe exhaustively the local criteria used by farmers to measure the agronomic performance of cowpea;2) assess the variability and statistical structure of these farmer criteria across local contexts;3) and analyze the association between these farmer criteria and the classical agronomic measurement. To achieve these objectives, an augmented block design was implemented across fifteen locations in the regions of Maradi, Dosso and Tillabéri, representing a diversity of local contexts. From a set of 36 cowpea varieties, fifteen varieties were sown per location, including five varieties (controls) common to all locations. In each location, two replicates were sown in randomized Fisher’s blocks. After agronomic measurement and participatory evaluation (scoring of varieties by farmers), a group survey (focus group) was conducted in each location to identify the criteria considered by farmers to found their discretional scoring of varieties during the participatory evaluation. The analysis of the data identified, across locations, thirteen criteria defined by farmers to characterize the agronomic performance of cowpea. Some of these criteria were different according to location. Farmers ranked the three varieties with the best performance for each agronomical trait (Top 3 varieties). A comparison of the farmer ranking with the ranking based on agronomic measurements revealed similarity and complementary between both methods. This study highlighted the importance of considering both local and scientific knowledge in local varietal evaluations.展开更多
The crown root system is the most important root component in maize at both the vegetative and reproductive stages. However, the genetic basis of maize crown root traits(CRT) is still unclear, and the relationship bet...The crown root system is the most important root component in maize at both the vegetative and reproductive stages. However, the genetic basis of maize crown root traits(CRT) is still unclear, and the relationship between CRT and aboveground agronomic traits in maize is poorly understood. In this study, an association panel including 531 elite maize inbred lines was planted to phenotype the CRT and aboveground agronomic traits in different field environments. We found that root traits were significantly and positively correlated with most aboveground agronomic traits, including flowering time, plant architecture and grain yield. Using a genome-wide association study(GWAS)coupled with resequencing, a total of 115 associated loci and 22 high-confidence candidate genes were identified for CRT. Approximately one-third of the genetic variation in crown root was co-located with 46 QTLs derived from flowering and plant architecture. Furthermore, 103 (89.6%) of 115 crown root loci were located within known domestication-and/or improvement-selective sweeps, suggesting that crown roots might experience indirect selection in maize during domestication and improvement. Furthermore, the expression of Zm00001d036901, a high-confidence candidate gene, may contribute to the phenotypic variation in maize crown roots, and Zm00001d036901 was selected during the domestication and improvement of maize. This study promotes our understanding of the genetic basis of root architecture and provides resources for genomics-enabled improvements in maize root architecture.展开更多
Garlic,an asexually propagated crop,is the second important bulb crop after the onion and is used as a vegetable and medicinal plant.Abundant and diverse garlic resources have been formed over thousands of years of cu...Garlic,an asexually propagated crop,is the second important bulb crop after the onion and is used as a vegetable and medicinal plant.Abundant and diverse garlic resources have been formed over thousands of years of cultivation.However,genome variation,population structure and genetic architecture of garlic agronomic traits were still not well elucidated.Here,1100258 single nucleotide polymorphisms(SNPs)were identified using genotyping-by-sequencing in 606 garlic accessions collected from43 countries.Population structure,principal component and phylogenetic analysis showed that these accessions were divided into five subpopulations.Twenty agronomic traits,including above-ground growth traits,bulb-related and bolt-related traits in two consecutive years were implemented in a genome-wide association study.In total,542 SNPs were associated with these agronomic traits,among which 188 SNPs were repeatedly associated with more than two traits.One SNP(chr6:1896135972)was repeatedly associated with ten traits.These associated SNPs were located within or near 858 genes,56 of which were transcription factors.Interestingly,one non-synonymous SNP(Chr4:166524085)in ribosomal protein S5 was repeatedly associated with above-ground growth and bulb-related traits.Additionally,gene ontology enrichment analysis of candidate genes for genomic selection regions between complete-bolting and non-bolting accessions showed that these genes were significantly enriched in‘vegetative to reproductive phase transition of meristem’,‘shoot system development’,‘reproductive process’,etc.These results provide valuable information for the reliable and efficient selection of candidate genes to achieve garlic genetic improvement and superior varieties.展开更多
Melon(Cucumis melo L.)is an important vegetable crop that has an extensive history of cultivation.However,the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet a...Melon(Cucumis melo L.)is an important vegetable crop that has an extensive history of cultivation.However,the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet available.Here we report a chromosome-level T2T genome assembly for 821(C.melo ssp.agrestis var.acidulus),a semi-wild melon with two haplotypes of∼373 Mb and∼364 Mb,respectively.Comparative genome analysis discovered a significant number of structural variants(SVs)between melo(C.melo ssp.melo)and agrestis(C.melo ssp.agrestis)genomes,including a copy number variation located in the ToLCNDV resistance locus on chromosome 11.Genome-wide association studies detected a significant signal associated with climacteric ripening and identified one candidate gene CM_ac12g14720.1(CmABA2),encoding a cytoplasmic short chain dehydrogenase/reductase,which controls the biosynthesis of abscisic acid.This study provides valuable genetic resources for future research on melon breeding.展开更多
Recent publications have highlighted significant progress in utilizing agronomic interventions to alleviate waterlogging stress in cotton production.Based on these advancements,we provide a concise comment on the effe...Recent publications have highlighted significant progress in utilizing agronomic interventions to alleviate waterlogging stress in cotton production.Based on these advancements,we provide a concise comment on the effects and underlying mechanisms of various strategies such as utilizing stress-tolerant cotton varieties,applying nitric oxide(NO),and implementing ridge intertillage.Finally,we recommend a combination of measures to enhance cotton’s ability to withstand waterlogging and reduce yield losses.展开更多
Upland cotton(Gossypium hirsutum)is the most important plant producing natural fibers for the textile industry.In this study,we first investigated the phenotypic variation of seven agronomic traits of 273 diverse cott...Upland cotton(Gossypium hirsutum)is the most important plant producing natural fibers for the textile industry.In this study,we first investigated the phenotypic variation of seven agronomic traits of 273 diverse cotton accessions in the years 2017 and 2018,which were from 18 geographical regions.We found large variations among the traits in different geographical regions and only half of the traits in either years 2017 or 2018 followed a normal distribution.We then genotyped the collection with 81,612 high quality SNPs.Phylogenetic tree and population structure revealed a diverse genetic structure of the core collection,and geographical diversification was an important factor,but account for part of the variances of genetic diversification.We then performed genome-wide association study for the seven traits in the years 2017 and 2018,and the average values of each trait in the two years,respectively.We identified a total of 19 significant marker-trait associations and found that Pollen Ole e 1 allergen/extension could be the candidate gene associated with the fall-off cotton bolls from the last three branches.In addition,large variations were observed for the heritability of traits in the years 2017 and 2018.These results provide new potential candidate genes for further functional validation,which could be useful for genetic improvement and breeding of new cotton cultivars with better agronomic performances.展开更多
Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest du...Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest due to a rapid post-harvest physiological deterioration (PPD) makes the roots to be considered as a risky product to market. The objectives of this work were to investigate the influence of two harvest periods on cassava agronomic parameters and their physiological response to PPD. Three cassava cultivars 96/1414, I070593 and LMR were selected for the experiment and harvested at 10 and 12 months after planting (MAP). The response to PPD was assessed during storage at 0, 3, 8 and 15 days after harvest (DAH). Total proteins content, soluble sugars and starch, total polyphenols compounds, polyphenoloxidase and peroxidase activities were recorded during storage. Results showed large variation among the parameters at the two harvest periods across the cultivars. High number of tubers was recorded in all the cultivars at 12 MAP and a significant increase in storage roots length was observed in 96/1414 and LMR from 10 MAP to 12 MAP (25 ± 5.1 to 41.3 ± 5.9 and 22.6 ± 3.3 to 27.9 ± 4.8) respectively. A reduction of about 49% of tubers weight was observed in I070593 from 10 to 12 MAP while an increase of about 36% and 11% were recorded in LMR and 96/1414 respectively. Tubers from I070593 showed less susceptibility to PPD when harvested at 10 MAP compared to those from LMR and 96/1414 where less susceptibility to PPD were recorded at 12 MAP. An increase in soluble sugars content, total proteins content and peroxidase activity subsequently to a decrease in starch content were recorded during storage from 8 to 15 days after harvest especially at 10 MAP in I070593 and at 12 MAP in LMR and 96/1414. High content of total phenolic compounds and less activity of polyphenol oxidase were correlated to PPD susceptibility. This work opens a new insight issue of the consideration of the appropriate harvest time of the cultivars as a tool to better control the onset of postharvest physiological deterioration.展开更多
It is commonly known that polyploidization has become one of major forces for a speciation and evolution, especially with evolutionary fixed potential agronomic traits in plants. Although several studies demonstrate t...It is commonly known that polyploidization has become one of major forces for a speciation and evolution, especially with evolutionary fixed potential agronomic traits in plants. Although several studies demonstrate that allopolyploid plants were successful in developing novel crops, autopolyploid ones are also more substantial and worth exploring. Obviously, autopolyploid development via sexual or asexual pathways can lead to advantages in biomass, changing process of development, and lots of benefits on coping with climate changes do not comprehend as a whole. This review shed light on 1) gaining gigantic effect and increasing phytochemical content;2) enhancing biotic and abiotic tolerance to adapt to climate change;3) changing in process of development;4) adapting ecology. Based on these benefits, this review provides breeders with several choices when they need in the breeding strategies. Also further review on prospects of polyploidy potato in food security is concerned.展开更多
Oil palm is cultivated by agro-industries and smallholders for vegetable oil production. Good farm management practices with balanced soil and plant macronutrients are needed to attain optimum yields. Smallholder oil ...Oil palm is cultivated by agro-industries and smallholders for vegetable oil production. Good farm management practices with balanced soil and plant macronutrients are needed to attain optimum yields. Smallholder oil palm farmers of Dibombari Sub-Division, Cameroon, suffer from low on farm yields which could emanate from the agronomic practices implemented, which also has an influence on the soil and plant macronutrient status. This study provides information on the agronomic practices, soil and plant macronutrients status in smallholder oil palm fields. Structured questionnaires were administered to 200 farmers to collect data on their agronomic practices, using a stratified random sampling design. Soil and plants were sampled from plantations of different age groups (control, >0 - 4 years, >4 - 8 years and >8 - 15 years’ plantations) in four locations of the Sub-Division (i.e. Dibombari-central, Bonamateke, Bomono and Nkapa) using a randomized complete block design. Data collected, was analyzed using descriptive and inferential statistics. The results showed that 65% of farmers planted Tenera variety, with majority of them below the standards for weeding (81%), fertilizer use (100%), pruning (62%), pest/disease control (90.5%) and harvesting (96%) practices. Soil macronutrients were low across the different plantations except P which was optimal at >0 - 4 years and >4 - 8 years’ plantations but low at >8 - 15 years’ plantation. Similarly, for plant macronutrients, N and P were optimal across the different plantations, while K and Mg were optimal at >0 - 4 years’ plantation but low at >4 - 8 years and >8 - 15 years’ plantations. Thus, agronomic practices and macronutrient status of soil and plants were below standards in smallholder oil palm plantations of Dibombari, leading to low yields of fresh fruit bunches.展开更多
Soybean is a main crop, and most agronomic traits of soybean are quantitative; therefore, there is vely important studying and applying value to locating these traits. A F2:10 RIL population containing 154 lines, der...Soybean is a main crop, and most agronomic traits of soybean are quantitative; therefore, there is vely important studying and applying value to locating these traits. A F2:10 RIL population containing 154 lines, derived from the cross between Charleston as female and Dongnong 594 as male parent, were used in this experiment. A genetic linkage map was constructed with 164 SSR primers, which were screened with the two parents and amplified on the 154 lines. 12 agronomic traits different between the two parents were investigated, and QTLs of all the traits were analyzed using the software Windows QTL Cartographer V2.0. The agronomic traits included quality traits: protein content, oil content, and content of protein and oil; yield traits: pods per plant, seed weight per plant, and 100 seeds weight; and other agronomic traits: plant height, days to maturity, branches, nod number in main stem, average leaf length, and average leaf width. The results showed that 68 QTLs in total were found for the 12 agronomic traits. The number of QTLs per trait varied from 3 for the average leaf width to 11 for 100 seeds weight and plant height, and was 5.8 on average. Good accordance was seen in many QTLs between the results of this study and the results obtained by other similar studies; therefore, these QTLs may be valuable for molecular marker assistant selection in soybean. In this study, 68 major QTLs of 12 important traits of soybean were analyzed.展开更多
Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling st...Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling stage, induces a significant loss in yield and results in poor grain quality. Stress caused by low light often creates severe meteorological disasters in some rice-growing regions worldwide. This review was based on our previous research and related research regarding the effects of low light on rice growth, yield and quality as well as the formation of grain, and mainly reviewed the physiological metabolism of rice plants, including characteristics of photosynthesis, activities of antioxidant enzymes in rice leaves and key enzymes involved in starch synthesis in grains, as well as the translocations of carbohydrate and nitrogen. These characteristics include various grain yield and rice quality components (milling and appearance as well as cooking, eating and nutritional qualities) under different rates of shading imposed at the vegetative or reproductive stages of rice plants. Furthermore, we discussed why grain yield and quality are reduced under the low light environment. Next, we summarized the need for future research that emphasizes methods can effectively improve rice grain yield and quality under low light stress. These research findings can provide a beneficial reference for rice cultivation management and breeding program in low light environments.展开更多
The gene Fhb1 has been used in many countries to improve wheat Fusarium head blight(FHB) resistance. To make better use of this gene in the Yellow-Huai River Valleys Winter Wheat Zone(YHWZ), the most important wheat-p...The gene Fhb1 has been used in many countries to improve wheat Fusarium head blight(FHB) resistance. To make better use of this gene in the Yellow-Huai River Valleys Winter Wheat Zone(YHWZ), the most important wheat-producing region of China, it is desirable to elucidate its effects on FHB resistance and agronomic traits in different genetic backgrounds. Based on a diagnostic marker for Fhb1, six BC2 populations were developed by crossing dwarf-male-sterile(DMS)-Zhoumai 16 to three Fhb1 donors(Ningmai 9, Ningmai 13, and Jianyang 84) and backcrossing to Zhoumai 16 and Zhoumai16’s derivative cultivars(Lunxuan 136 and Lunxuan 13) using marker-assisted backcross breeding. The progenies were assessed for FHB resistance and major agronomic traits.The Fhb1 alleles were identified using the gene-specific molecular marker. The plants with the Fhb1-resistant genotype(Fhb1-R) in these populations showed significantly fewer infected spikelets than those with the Fhb1-susceptible genotype(Fhb1-S). When Lunxuan 136 was used as the recurrent parent, Fhb1-R plants showed significantly fewer infected spikelets per spike than Fhb1-R plants produced using Lunxuan 13 as the recurrent parent, indicating that the genetic backgrounds of Fhb1 influence the expression of FHB resistance. Fhb1-R plants from the DMS-Zhoumai 16/Ningmai 9//Zhoumai 16/3/Lunxuan 136 population showed the highest FHB resistance among the six populations and a significantly higher level of FHB resistance than the moderately susceptible control Huaimai 20. No significant phenotypic differences between Fhb1-R and Fhb1-S plants were observed for the eight agronomic traits investigated. These results suggest that it is feasible to improve FHB resistance of winter wheat withoutreducing yield potential by introgressing Fhb1 resistance allele into FHB-susceptible cultivars in the YHWZ.展开更多
Crop yield potential can be increased through the use of appropriate agronomic practices. Integrated agronomic practice (IAP) is an effective way to increase maize (Zea mays L.) grain yield and nitrogen use efficiency...Crop yield potential can be increased through the use of appropriate agronomic practices. Integrated agronomic practice (IAP) is an effective way to increase maize (Zea mays L.) grain yield and nitrogen use efficiency (NUE);however, the physiological processes associated with gains in yield potential obtained from IAP, particularly the different under various soil fertility conditions, remain poorly understood. An IAP strategy including optimal planting density, split fertilizer application, and subsoiling tillage was evaluated over two growing seasons to determine whether the effects of IAP on maize yield and NUE differ under different levels of soil fertility. Compared to farmers' practices (FP), IAP increased maize grain yield in 2013 and 2014 by 25% and 28%, respectively, in low soil fertility (LSF) fields and by 36% and 37%, respectively, in high soil fertility (HSF) fields. The large yield gap was attributed mainly to greater dry matter (DM) and N accumulation with IAP than with FP owing to increased leaf area index (LAI) and DM accumulation rate, which were promoted by greater soil mineral N content (Nmin) and root length. Post-silking DM and N accumulation were also greater with IAP than with FP under HSF conditions, accounting for 60% and 43%, respectively, of total biomass and N accumulation;however, no significant differences were found for post-silking DM and N accumulation between IAP and FP under LSF conditions. Thus, the increase in grain yield with IAP was greater under HSF than under LSF. Because of greater grain yield and N uptake, IAP significantly increased N partial factor productivity, agronomic N efficiency, N recovery efficiency, and physiological efficiency of applied N compared to FP, particularly in the HSF fields. These results indicate that considerable further increases in yield and NUE can be obtained by increasing effective soil N content and maize root length to promote post-silking N and DM accumulation in maize planted at high plant density, especially in fields with low soil fertility.展开更多
Aegiliops tauschii is classified into two subspecies: Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata. Novel genetic variations exist in Ae. tauschii ssp. tauschii that can be utilized in wheat improveme...Aegiliops tauschii is classified into two subspecies: Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata. Novel genetic variations exist in Ae. tauschii ssp. tauschii that can be utilized in wheat improvement. We synthesized a hexaploid wheat genotype(SHW-L1) by crossing an Ae. tauschii ssp. tauschii accession(AS60) with a tetraploid wheat genotype(AS2255). A population consisting of 171 F8 recombinant inbred lines was developed from SHW-L1 and Chuanmai 32 to identify QTLs associated with agronomic traits. A new genetic map with high density was constructed and used to detect the QTLs for heading date, kernel width, spike length, spikelet number, and thousand kernel weight. A total of 30 putative QTLs were identified for five investigated traits. Thirteen QTLs were located on D genomes of SHW-L1, six of them showed positive effect on agronomic traits. Chromosome region flanked by wPt-6133–wPt-8134 on 2D carried five environment-independent QTLs. Each QTL accounted for more than 10% phenotypic variance. These QTLs were highly consistent across environments and should be used in wheat breeding.展开更多
Single segment substitution lines (SSSLs) each with a single chromosome segment from a donor under the same genetic background as the recipient were developed in rice by advanced backcrossing and molecular marker-as...Single segment substitution lines (SSSLs) each with a single chromosome segment from a donor under the same genetic background as the recipient were developed in rice by advanced backcrossing and molecular marker-assisted selection. Using the SSSLs, the QTLs for the important agronomic traits in rice would be detected under different environmental conditions. Detection of the QTLs controlling 22 important traits in rice was done with 32 SSSLs by the randomized block design in 2-4 cropping seasons. 59 QTLs were detected and distributed on chromosomes 1, 2, 3, 4, 6, 7, 8, 10, and 11, of which 18 QTLs were detected more than twice. Only 30.5% of the QTLs were detected repeatedly in different cropping seasons. Most of the QTLs of important agronomic traits were of little additive effects and instability. The QTLs controlling the traits, such as grain weight, grain length, ratio of grain length to width, and heading date were relatively stable. The stable QTLs usually had larger additive effects and were less affected by environment. The QTLs for the important agronomic traits were detected using the SSSLs in rice with high resolution under different environmental conditions. The instability of the QTLs may be the basis of the variation of rice plants during growth and development. It would be the genetic basis for improving yield and quality in rice cultivars by farming methods.展开更多
Rice research has always been the top priority in China and China produces the highest number of scientific journal papers on rice, particularly on rice genetics and breeding. In this study, we used a bibliometric app...Rice research has always been the top priority in China and China produces the highest number of scientific journal papers on rice, particularly on rice genetics and breeding. In this study, we used a bibliometric approach to analyze the trends of papers published by Chinese researchers on rice physiology and management. Data were collected from three major agronomic journals(i.e., Agronomy Journal, Crop Science, and Field Crops Research) by searching in the Web of Science on September 8, 2017. A total of 186 rice papers were published by Chinese researchers on crop physiology and management in the three journals since their establishment. Yearly average number of such papers was 1.6, 6.5, and 21.0 for the periods of 1993–2005, 2006–2011, and 2012–2017, respectively. Their quality in terms of citation performance has also improved significantly in the recent decade. Huazhong Agricultural University, Yangzhou University, and Nanjing Agricultural University were leading organizations and published 54.4% of all 186 papers. Huang Min of Hunan Agricultural University and Peng Shaobing of Huazhong Agricultural University published the most number of rice papers on crop physiology and management as the first and corresponding authors, respectively. Yield potential and nitrogen-related research such as nitrogen use efficiency, nitrogen management, and plant nitrogen diagnosis have been the research focuses for rice crop. In recent years, research on global warming including high temperature stress, direct seeding, zero tillage, Bt rice, and critical nitrogen dilution curve were becoming popular. New research is emerging on yield gap, rice ratooning, and simplified and reduced-input practices in rice production.展开更多
With an increasing population and changing diet structure, summer maize is increasingly becoming an important energy crop in China. However, traditional farmer practices for maize production are inefficient and unsust...With an increasing population and changing diet structure, summer maize is increasingly becoming an important energy crop in China. However, traditional farmer practices for maize production are inefficient and unsustainable. To ensure food security and sustainable development of summer maize production in China, an improved, more sustainable farmer management system is needed. Establishing this system requires a comprehensive understanding of the limitations of current farming practice and the ways it could be improved. In our study, 235 plots from three villages in the North China Plain(NCP) were monitored. Maize production on farms was evaluated;our results showed that the maize yield and nitrogen partial factor productivity(PFPN) were variable on smallholder farms at 6.6–13.7 t ha^–1 and 15.4–88.7 kg kg^–1, respectively.Traditional farming practices also have a large environmental impact(nitrogen surplus:–64.2–323.78 kg ha^–1). Key yield components were identified by agronomic diagnosis. Grain yield depend heavily on grain numbers per hectare rather than on the 1 000-grain weight. A set of improved management practices(IP) for maize production was designed by employing a boundary line(BL) approach and tested on farms. Results showed that the IP could increase yield by 18.4% and PFPN by 31.1%, compared with traditional farmer practices(FP), and reduce the nitrogen(N) surplus by 57.9 kg ha^–1. However,in terms of IP effect, there was a large heterogeneity among different smallholder farmers’ fields, meaning that, precise technologies were needed in different sites especially for N fertilizer management. Our results are valuable for policymakers and smallholder farmers for meeting the objectives of green development in agricultural production.展开更多
文摘This study evaluated the genetic and agronomic parameter estimates of maize under different nitrogen rates. The trial was established at the Njala Agricultural Research Centre experimental site during 2021 and 2022 in a split block design with three maize varieties (IWCD2, 2009EVDT, and DMR-ESR-Yellow) and seven nitrogen (0, 30, 60, 90, 120, 150 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup>) rates. Findings showed that cob diameter and anthesis silking time (ASI) had intermediate heritability, ASI had high genetic advance, ASI and grain yield had high genotypic coefficient of variation (GCV), while traits with high phenotypic coefficient of variation (PCV) were plant height, ASI, grain yield, number of kernel per cob, number of kernel rows, ear length, and ear height. The PCV values were higher than GCV, indicating the influence of the environment in the studied traits. Nitrogen rates and variety significantly (p < 0.05) influenced grain yield production. Mean grain yields and economic parameter estimates increased with increasing nitrogen rates, with the 30 and 180 kg∙N∙ha<sup>−</sup><sup>1</sup> plots exhibiting the lowest and highest grain yields of 1238 kg∙ha<sup>−</sup><sup>1</sup> and 2098 kg∙ha<sup>−</sup><sup>1</sup>, respectively. Variety and nitrogen effects on partial factor productivity (PFP<sub>N</sub>), agronomic efficiency (AEN), net returns (NR), value cost ratio (VCR) and marginal return (MR) indicated that these parameters were significantly affected (p < 0.05) by these factors. The highest PFP<sub>N</sub> (41.3 kg grain kg<sup>−</sup><sup>1</sup>∙N) and AEN (29.4 kg grain kg<sup>−</sup><sup>1</sup>∙N) were obtained in the 30 kg∙N∙ha<sup>−</sup><sup>1</sup> plots, while the highest VCR (2.8) and MR (SLL 1.8 SLL<sup>−</sup><sup>1</sup> spent on N) were obtained in the 180 kg∙N∙ha<sup>−</sup><sup>1</sup>. The significant influence of variety and nitrogen on traits suggests that increasing yields and maximizing profits require use of appropriate nitrogen fertilization and improved farming practices that could be exploited for increased productivity of maize.
基金Supported by Key R&D Project of Henan Province(231111110300)National Modern Agricultural Industry Technology System Special Fund Project of Ministry of Finance/Ministry of Agriculture and Rural Affairs(nycytx-CARS-06)+1 种基金Science and Technology Innovation Team Project of Henan Academy of Agricultural Sciences(2022KJCHXTD33)Henan Provincial Agricultural Seed Research Project(2022010401).
文摘[Objectives]To find out a suitable cultivation technique of Wangu 098 in Nanyang area,speed up the popularization,demonstration and application of Wangu 098,and provide a theoretical and practical basis for adjusting the planting structure and realizing the matching of improved varieties and methods.[Methods]The new self-bred millet variety Wangu 098 was used as the material,and the two-factor split zone experimental design was adopted.The effects of different sowing dates and densities on the yield,growth period and agronomic characters of millet were studied.[Results]The interaction of seeding date and density had a great effect on the yield and plant traits of millet.Millet yield was significantly and positively correlated with plant height,panicle length,single panicle weight,panicle grain weight and tiller number.[Conclusions]The reasonable combination of seeding date and density could give full play to the yield potential of millet.According to the experimental results and cultivation experience,the suitable seeding date of millet in Nanyang area is in the first and middle ten days of June,and the best density is about 750000 plants/ha.However,after June 30,the seeding millet did not tiller,so the density should be increased to more than 900000 plants/ha to obtain higher yield.In terms of cultivation and management,timely seeding,reasonable close planting,and coordination of vegetative growth and reproductive growth can make the plant tall and strong,panicle long and thick,and improve the yield of millet.
基金Supported by High-level Talents Project of Basic and Applied Basic Research Program(Natural Science Field)of Hainan Province(320RC715)Earmarked Fund for China Agricultural Research System(CARS-170716).
文摘[Objectives]Sugarcane is the most significant sugar cash crop in the tropical and subtropical regions of China.However,it is notable for its narrow genetic basis,limited trait improvement,weak adaptability of varieties,and poor planting efficiency.In order to accelerate the process of sugarcane variety replacement and expand the basis of genetic variation,interspecific hybridization and multiple mutagenesis are the most effective methods for obtaining new sugarcane varieties.The evaluation and identification of phenotypic traits of germplasm represents a significant analytical method.The"Zhongtang"series of sugarcane varieties is distinguished by its high yield and high sugar content.New sugarcane germplasms with excellent agronomic and quality traits can be identified and developed as breeding parents and new breeding lines through comprehensive evaluation of the existing germplasm.[Methods]A total of 181 new lines were selected through genetic origin and orientation,and evaluated and appraised for growth,yield,and economic characteristics.The data on 6 important agronomic and quality traits,including tillering,initial plant height,plant height,stem diameter,number of effective stems,and brix at maturity,were used to discover superior lines.These traits were evaluated during the two production seasons of the participant lines.[Results]A comprehensive evaluation of seedling growth traits and economic traits at maturity of the experimental lines identified 30 excellent new germplasms of sugarcane.Among the selected lines,1501 and 1701 exhibited superior agronomic and quality traits,rendering them suitable as parental lines for sugarcane breeding or breeding as new varieties.[Conclusions]The exemplary results obtained in this study provide a solid foundation for the improvement of sugarcane germplasm,with the goal of enhancing quality and efficiency.These findings are of great scientific and practical significance to the study of sugarcane yield and sugar-related genes,as well as the exploration of the evaluation and utilization of sugarcane germplasm resources.
文摘When contributing to participatory research, farmers usually appreciate the performance of cowpea varieties using qualitative scores. The score they attribute to each variety are based on local knowledge. The specific criteria they individually use to attribute a score are not well described. The objectives of this work were to: 1) identify and describe exhaustively the local criteria used by farmers to measure the agronomic performance of cowpea;2) assess the variability and statistical structure of these farmer criteria across local contexts;3) and analyze the association between these farmer criteria and the classical agronomic measurement. To achieve these objectives, an augmented block design was implemented across fifteen locations in the regions of Maradi, Dosso and Tillabéri, representing a diversity of local contexts. From a set of 36 cowpea varieties, fifteen varieties were sown per location, including five varieties (controls) common to all locations. In each location, two replicates were sown in randomized Fisher’s blocks. After agronomic measurement and participatory evaluation (scoring of varieties by farmers), a group survey (focus group) was conducted in each location to identify the criteria considered by farmers to found their discretional scoring of varieties during the participatory evaluation. The analysis of the data identified, across locations, thirteen criteria defined by farmers to characterize the agronomic performance of cowpea. Some of these criteria were different according to location. Farmers ranked the three varieties with the best performance for each agronomical trait (Top 3 varieties). A comparison of the farmer ranking with the ranking based on agronomic measurements revealed similarity and complementary between both methods. This study highlighted the importance of considering both local and scientific knowledge in local varietal evaluations.
基金supported by grants from the National Natural Science Foundation of China (31971891)the Guangxi Key Research and Development Projects, China (GuikeAB21238004)+1 种基金the Scientific Innovation 2030 Project, China (2022ZD0401703)the Modern AgroIndustry Technology Research System of Maize, China (CARS-02-03)。
文摘The crown root system is the most important root component in maize at both the vegetative and reproductive stages. However, the genetic basis of maize crown root traits(CRT) is still unclear, and the relationship between CRT and aboveground agronomic traits in maize is poorly understood. In this study, an association panel including 531 elite maize inbred lines was planted to phenotype the CRT and aboveground agronomic traits in different field environments. We found that root traits were significantly and positively correlated with most aboveground agronomic traits, including flowering time, plant architecture and grain yield. Using a genome-wide association study(GWAS)coupled with resequencing, a total of 115 associated loci and 22 high-confidence candidate genes were identified for CRT. Approximately one-third of the genetic variation in crown root was co-located with 46 QTLs derived from flowering and plant architecture. Furthermore, 103 (89.6%) of 115 crown root loci were located within known domestication-and/or improvement-selective sweeps, suggesting that crown roots might experience indirect selection in maize during domestication and improvement. Furthermore, the expression of Zm00001d036901, a high-confidence candidate gene, may contribute to the phenotypic variation in maize crown roots, and Zm00001d036901 was selected during the domestication and improvement of maize. This study promotes our understanding of the genetic basis of root architecture and provides resources for genomics-enabled improvements in maize root architecture.
基金supported by the Natural Science Foundation of China(31872946,32172566,and 32272731)National Key R&D Program of China(2021YFD1200201),China Agriculture Research System of MOF and MARA(CARS-24-A-01)+4 种基金Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CAAS-XTCX2018021)Youth Innovation Special Task of Chinese Academy of Agricultural Sciences(Y2023QC06)Agricultural Basic Long-Term Scientific and TechnologicalWork(NAES-GR-005)Safe Preservation Project of Crop Germplasm Resources of MOF(2022NWB037)National Hoticultural Gerplasm Centre Project(NHGRC2022-NH01).
文摘Garlic,an asexually propagated crop,is the second important bulb crop after the onion and is used as a vegetable and medicinal plant.Abundant and diverse garlic resources have been formed over thousands of years of cultivation.However,genome variation,population structure and genetic architecture of garlic agronomic traits were still not well elucidated.Here,1100258 single nucleotide polymorphisms(SNPs)were identified using genotyping-by-sequencing in 606 garlic accessions collected from43 countries.Population structure,principal component and phylogenetic analysis showed that these accessions were divided into five subpopulations.Twenty agronomic traits,including above-ground growth traits,bulb-related and bolt-related traits in two consecutive years were implemented in a genome-wide association study.In total,542 SNPs were associated with these agronomic traits,among which 188 SNPs were repeatedly associated with more than two traits.One SNP(chr6:1896135972)was repeatedly associated with ten traits.These associated SNPs were located within or near 858 genes,56 of which were transcription factors.Interestingly,one non-synonymous SNP(Chr4:166524085)in ribosomal protein S5 was repeatedly associated with above-ground growth and bulb-related traits.Additionally,gene ontology enrichment analysis of candidate genes for genomic selection regions between complete-bolting and non-bolting accessions showed that these genes were significantly enriched in‘vegetative to reproductive phase transition of meristem’,‘shoot system development’,‘reproductive process’,etc.These results provide valuable information for the reliable and efficient selection of candidate genes to achieve garlic genetic improvement and superior varieties.
基金This work was supported by funding from the Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2016-ZFRI-06)the China Agriculture Research System(CARS-25-2023-G6)+3 种基金the Key Research and Development Program of Hainan(ZDYF2021XDNY164)the European Research Council(ERC-NectarGland,101095736)the 111 Project(B17043)Henan Province Science and Technology Research Project(232102110185).
文摘Melon(Cucumis melo L.)is an important vegetable crop that has an extensive history of cultivation.However,the genome of wild and semi-wild melon types that can be used for the analysis of agronomic traits is not yet available.Here we report a chromosome-level T2T genome assembly for 821(C.melo ssp.agrestis var.acidulus),a semi-wild melon with two haplotypes of∼373 Mb and∼364 Mb,respectively.Comparative genome analysis discovered a significant number of structural variants(SVs)between melo(C.melo ssp.melo)and agrestis(C.melo ssp.agrestis)genomes,including a copy number variation located in the ToLCNDV resistance locus on chromosome 11.Genome-wide association studies detected a significant signal associated with climacteric ripening and identified one candidate gene CM_ac12g14720.1(CmABA2),encoding a cytoplasmic short chain dehydrogenase/reductase,which controls the biosynthesis of abscisic acid.This study provides valuable genetic resources for future research on melon breeding.
基金National Natural Science Foundation of China(31771718,31801307).
文摘Recent publications have highlighted significant progress in utilizing agronomic interventions to alleviate waterlogging stress in cotton production.Based on these advancements,we provide a concise comment on the effects and underlying mechanisms of various strategies such as utilizing stress-tolerant cotton varieties,applying nitric oxide(NO),and implementing ridge intertillage.Finally,we recommend a combination of measures to enhance cotton’s ability to withstand waterlogging and reduce yield losses.
基金supported by the Xinjiang Uygur Autonomous Region Major Science and Technology Project (2021A02001-3).
文摘Upland cotton(Gossypium hirsutum)is the most important plant producing natural fibers for the textile industry.In this study,we first investigated the phenotypic variation of seven agronomic traits of 273 diverse cotton accessions in the years 2017 and 2018,which were from 18 geographical regions.We found large variations among the traits in different geographical regions and only half of the traits in either years 2017 or 2018 followed a normal distribution.We then genotyped the collection with 81,612 high quality SNPs.Phylogenetic tree and population structure revealed a diverse genetic structure of the core collection,and geographical diversification was an important factor,but account for part of the variances of genetic diversification.We then performed genome-wide association study for the seven traits in the years 2017 and 2018,and the average values of each trait in the two years,respectively.We identified a total of 19 significant marker-trait associations and found that Pollen Ole e 1 allergen/extension could be the candidate gene associated with the fall-off cotton bolls from the last three branches.In addition,large variations were observed for the heritability of traits in the years 2017 and 2018.These results provide new potential candidate genes for further functional validation,which could be useful for genetic improvement and breeding of new cotton cultivars with better agronomic performances.
文摘Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest due to a rapid post-harvest physiological deterioration (PPD) makes the roots to be considered as a risky product to market. The objectives of this work were to investigate the influence of two harvest periods on cassava agronomic parameters and their physiological response to PPD. Three cassava cultivars 96/1414, I070593 and LMR were selected for the experiment and harvested at 10 and 12 months after planting (MAP). The response to PPD was assessed during storage at 0, 3, 8 and 15 days after harvest (DAH). Total proteins content, soluble sugars and starch, total polyphenols compounds, polyphenoloxidase and peroxidase activities were recorded during storage. Results showed large variation among the parameters at the two harvest periods across the cultivars. High number of tubers was recorded in all the cultivars at 12 MAP and a significant increase in storage roots length was observed in 96/1414 and LMR from 10 MAP to 12 MAP (25 ± 5.1 to 41.3 ± 5.9 and 22.6 ± 3.3 to 27.9 ± 4.8) respectively. A reduction of about 49% of tubers weight was observed in I070593 from 10 to 12 MAP while an increase of about 36% and 11% were recorded in LMR and 96/1414 respectively. Tubers from I070593 showed less susceptibility to PPD when harvested at 10 MAP compared to those from LMR and 96/1414 where less susceptibility to PPD were recorded at 12 MAP. An increase in soluble sugars content, total proteins content and peroxidase activity subsequently to a decrease in starch content were recorded during storage from 8 to 15 days after harvest especially at 10 MAP in I070593 and at 12 MAP in LMR and 96/1414. High content of total phenolic compounds and less activity of polyphenol oxidase were correlated to PPD susceptibility. This work opens a new insight issue of the consideration of the appropriate harvest time of the cultivars as a tool to better control the onset of postharvest physiological deterioration.
文摘It is commonly known that polyploidization has become one of major forces for a speciation and evolution, especially with evolutionary fixed potential agronomic traits in plants. Although several studies demonstrate that allopolyploid plants were successful in developing novel crops, autopolyploid ones are also more substantial and worth exploring. Obviously, autopolyploid development via sexual or asexual pathways can lead to advantages in biomass, changing process of development, and lots of benefits on coping with climate changes do not comprehend as a whole. This review shed light on 1) gaining gigantic effect and increasing phytochemical content;2) enhancing biotic and abiotic tolerance to adapt to climate change;3) changing in process of development;4) adapting ecology. Based on these benefits, this review provides breeders with several choices when they need in the breeding strategies. Also further review on prospects of polyploidy potato in food security is concerned.
文摘Oil palm is cultivated by agro-industries and smallholders for vegetable oil production. Good farm management practices with balanced soil and plant macronutrients are needed to attain optimum yields. Smallholder oil palm farmers of Dibombari Sub-Division, Cameroon, suffer from low on farm yields which could emanate from the agronomic practices implemented, which also has an influence on the soil and plant macronutrient status. This study provides information on the agronomic practices, soil and plant macronutrients status in smallholder oil palm fields. Structured questionnaires were administered to 200 farmers to collect data on their agronomic practices, using a stratified random sampling design. Soil and plants were sampled from plantations of different age groups (control, >0 - 4 years, >4 - 8 years and >8 - 15 years’ plantations) in four locations of the Sub-Division (i.e. Dibombari-central, Bonamateke, Bomono and Nkapa) using a randomized complete block design. Data collected, was analyzed using descriptive and inferential statistics. The results showed that 65% of farmers planted Tenera variety, with majority of them below the standards for weeding (81%), fertilizer use (100%), pruning (62%), pest/disease control (90.5%) and harvesting (96%) practices. Soil macronutrients were low across the different plantations except P which was optimal at >0 - 4 years and >4 - 8 years’ plantations but low at >8 - 15 years’ plantation. Similarly, for plant macronutrients, N and P were optimal across the different plantations, while K and Mg were optimal at >0 - 4 years’ plantation but low at >4 - 8 years and >8 - 15 years’ plantations. Thus, agronomic practices and macronutrient status of soil and plants were below standards in smallholder oil palm plantations of Dibombari, leading to low yields of fresh fruit bunches.
文摘Soybean is a main crop, and most agronomic traits of soybean are quantitative; therefore, there is vely important studying and applying value to locating these traits. A F2:10 RIL population containing 154 lines, derived from the cross between Charleston as female and Dongnong 594 as male parent, were used in this experiment. A genetic linkage map was constructed with 164 SSR primers, which were screened with the two parents and amplified on the 154 lines. 12 agronomic traits different between the two parents were investigated, and QTLs of all the traits were analyzed using the software Windows QTL Cartographer V2.0. The agronomic traits included quality traits: protein content, oil content, and content of protein and oil; yield traits: pods per plant, seed weight per plant, and 100 seeds weight; and other agronomic traits: plant height, days to maturity, branches, nod number in main stem, average leaf length, and average leaf width. The results showed that 68 QTLs in total were found for the 12 agronomic traits. The number of QTLs per trait varied from 3 for the average leaf width to 11 for 100 seeds weight and plant height, and was 5.8 on average. Good accordance was seen in many QTLs between the results of this study and the results obtained by other similar studies; therefore, these QTLs may be valuable for molecular marker assistant selection in soybean. In this study, 68 major QTLs of 12 important traits of soybean were analyzed.
文摘Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling stage, induces a significant loss in yield and results in poor grain quality. Stress caused by low light often creates severe meteorological disasters in some rice-growing regions worldwide. This review was based on our previous research and related research regarding the effects of low light on rice growth, yield and quality as well as the formation of grain, and mainly reviewed the physiological metabolism of rice plants, including characteristics of photosynthesis, activities of antioxidant enzymes in rice leaves and key enzymes involved in starch synthesis in grains, as well as the translocations of carbohydrate and nitrogen. These characteristics include various grain yield and rice quality components (milling and appearance as well as cooking, eating and nutritional qualities) under different rates of shading imposed at the vegetative or reproductive stages of rice plants. Furthermore, we discussed why grain yield and quality are reduced under the low light environment. Next, we summarized the need for future research that emphasizes methods can effectively improve rice grain yield and quality under low light stress. These research findings can provide a beneficial reference for rice cultivation management and breeding program in low light environments.
基金supported by the National Key Research and Development Program of China (2016YFD0101802, 2017YFD010060)the National Natural Science Foundation of China (31771881, 31401468)the Agricultural Science and Technology Innovation Program
文摘The gene Fhb1 has been used in many countries to improve wheat Fusarium head blight(FHB) resistance. To make better use of this gene in the Yellow-Huai River Valleys Winter Wheat Zone(YHWZ), the most important wheat-producing region of China, it is desirable to elucidate its effects on FHB resistance and agronomic traits in different genetic backgrounds. Based on a diagnostic marker for Fhb1, six BC2 populations were developed by crossing dwarf-male-sterile(DMS)-Zhoumai 16 to three Fhb1 donors(Ningmai 9, Ningmai 13, and Jianyang 84) and backcrossing to Zhoumai 16 and Zhoumai16’s derivative cultivars(Lunxuan 136 and Lunxuan 13) using marker-assisted backcross breeding. The progenies were assessed for FHB resistance and major agronomic traits.The Fhb1 alleles were identified using the gene-specific molecular marker. The plants with the Fhb1-resistant genotype(Fhb1-R) in these populations showed significantly fewer infected spikelets than those with the Fhb1-susceptible genotype(Fhb1-S). When Lunxuan 136 was used as the recurrent parent, Fhb1-R plants showed significantly fewer infected spikelets per spike than Fhb1-R plants produced using Lunxuan 13 as the recurrent parent, indicating that the genetic backgrounds of Fhb1 influence the expression of FHB resistance. Fhb1-R plants from the DMS-Zhoumai 16/Ningmai 9//Zhoumai 16/3/Lunxuan 136 population showed the highest FHB resistance among the six populations and a significantly higher level of FHB resistance than the moderately susceptible control Huaimai 20. No significant phenotypic differences between Fhb1-R and Fhb1-S plants were observed for the eight agronomic traits investigated. These results suggest that it is feasible to improve FHB resistance of winter wheat withoutreducing yield potential by introgressing Fhb1 resistance allele into FHB-susceptible cultivars in the YHWZ.
基金supported by the Key National Research and Development Program of China (2016YFD0300207, 2016YFD0300103)the China Agriculture Research System (CRRS-02)
文摘Crop yield potential can be increased through the use of appropriate agronomic practices. Integrated agronomic practice (IAP) is an effective way to increase maize (Zea mays L.) grain yield and nitrogen use efficiency (NUE);however, the physiological processes associated with gains in yield potential obtained from IAP, particularly the different under various soil fertility conditions, remain poorly understood. An IAP strategy including optimal planting density, split fertilizer application, and subsoiling tillage was evaluated over two growing seasons to determine whether the effects of IAP on maize yield and NUE differ under different levels of soil fertility. Compared to farmers' practices (FP), IAP increased maize grain yield in 2013 and 2014 by 25% and 28%, respectively, in low soil fertility (LSF) fields and by 36% and 37%, respectively, in high soil fertility (HSF) fields. The large yield gap was attributed mainly to greater dry matter (DM) and N accumulation with IAP than with FP owing to increased leaf area index (LAI) and DM accumulation rate, which were promoted by greater soil mineral N content (Nmin) and root length. Post-silking DM and N accumulation were also greater with IAP than with FP under HSF conditions, accounting for 60% and 43%, respectively, of total biomass and N accumulation;however, no significant differences were found for post-silking DM and N accumulation between IAP and FP under LSF conditions. Thus, the increase in grain yield with IAP was greater under HSF than under LSF. Because of greater grain yield and N uptake, IAP significantly increased N partial factor productivity, agronomic N efficiency, N recovery efficiency, and physiological efficiency of applied N compared to FP, particularly in the HSF fields. These results indicate that considerable further increases in yield and NUE can be obtained by increasing effective soil N content and maize root length to promote post-silking N and DM accumulation in maize planted at high plant density, especially in fields with low soil fertility.
基金supported by the National Natural Science Foundation of China(31171556,31171555,31230053)the National High-Tech R&D Program of China(2011AA100103-02)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2013BAD01B02-9)
文摘Aegiliops tauschii is classified into two subspecies: Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata. Novel genetic variations exist in Ae. tauschii ssp. tauschii that can be utilized in wheat improvement. We synthesized a hexaploid wheat genotype(SHW-L1) by crossing an Ae. tauschii ssp. tauschii accession(AS60) with a tetraploid wheat genotype(AS2255). A population consisting of 171 F8 recombinant inbred lines was developed from SHW-L1 and Chuanmai 32 to identify QTLs associated with agronomic traits. A new genetic map with high density was constructed and used to detect the QTLs for heading date, kernel width, spike length, spikelet number, and thousand kernel weight. A total of 30 putative QTLs were identified for five investigated traits. Thirteen QTLs were located on D genomes of SHW-L1, six of them showed positive effect on agronomic traits. Chromosome region flanked by wPt-6133–wPt-8134 on 2D carried five environment-independent QTLs. Each QTL accounted for more than 10% phenotypic variance. These QTLs were highly consistent across environments and should be used in wheat breeding.
基金the National Natural Science Foundation of China (30330370).
文摘Single segment substitution lines (SSSLs) each with a single chromosome segment from a donor under the same genetic background as the recipient were developed in rice by advanced backcrossing and molecular marker-assisted selection. Using the SSSLs, the QTLs for the important agronomic traits in rice would be detected under different environmental conditions. Detection of the QTLs controlling 22 important traits in rice was done with 32 SSSLs by the randomized block design in 2-4 cropping seasons. 59 QTLs were detected and distributed on chromosomes 1, 2, 3, 4, 6, 7, 8, 10, and 11, of which 18 QTLs were detected more than twice. Only 30.5% of the QTLs were detected repeatedly in different cropping seasons. Most of the QTLs of important agronomic traits were of little additive effects and instability. The QTLs controlling the traits, such as grain weight, grain length, ratio of grain length to width, and heading date were relatively stable. The stable QTLs usually had larger additive effects and were less affected by environment. The QTLs for the important agronomic traits were detected using the SSSLs in rice with high resolution under different environmental conditions. The instability of the QTLs may be the basis of the variation of rice plants during growth and development. It would be the genetic basis for improving yield and quality in rice cultivars by farming methods.
基金supported by the National High Technology Research and Development Program of China (the 863 Project, 2014AA10A605)the Programme of Introducing Talents of Discipline to Universities in China (the 111 Project, B14032)the Program for Changjiang Scholars and Innovative Research Team in University of China (IRT1247)
文摘Rice research has always been the top priority in China and China produces the highest number of scientific journal papers on rice, particularly on rice genetics and breeding. In this study, we used a bibliometric approach to analyze the trends of papers published by Chinese researchers on rice physiology and management. Data were collected from three major agronomic journals(i.e., Agronomy Journal, Crop Science, and Field Crops Research) by searching in the Web of Science on September 8, 2017. A total of 186 rice papers were published by Chinese researchers on crop physiology and management in the three journals since their establishment. Yearly average number of such papers was 1.6, 6.5, and 21.0 for the periods of 1993–2005, 2006–2011, and 2012–2017, respectively. Their quality in terms of citation performance has also improved significantly in the recent decade. Huazhong Agricultural University, Yangzhou University, and Nanjing Agricultural University were leading organizations and published 54.4% of all 186 papers. Huang Min of Hunan Agricultural University and Peng Shaobing of Huazhong Agricultural University published the most number of rice papers on crop physiology and management as the first and corresponding authors, respectively. Yield potential and nitrogen-related research such as nitrogen use efficiency, nitrogen management, and plant nitrogen diagnosis have been the research focuses for rice crop. In recent years, research on global warming including high temperature stress, direct seeding, zero tillage, Bt rice, and critical nitrogen dilution curve were becoming popular. New research is emerging on yield gap, rice ratooning, and simplified and reduced-input practices in rice production.
基金supported by the National Basic Research Program of China (2015CB150405)the National Key R&D Program of China (2016YFD0200401)
文摘With an increasing population and changing diet structure, summer maize is increasingly becoming an important energy crop in China. However, traditional farmer practices for maize production are inefficient and unsustainable. To ensure food security and sustainable development of summer maize production in China, an improved, more sustainable farmer management system is needed. Establishing this system requires a comprehensive understanding of the limitations of current farming practice and the ways it could be improved. In our study, 235 plots from three villages in the North China Plain(NCP) were monitored. Maize production on farms was evaluated;our results showed that the maize yield and nitrogen partial factor productivity(PFPN) were variable on smallholder farms at 6.6–13.7 t ha^–1 and 15.4–88.7 kg kg^–1, respectively.Traditional farming practices also have a large environmental impact(nitrogen surplus:–64.2–323.78 kg ha^–1). Key yield components were identified by agronomic diagnosis. Grain yield depend heavily on grain numbers per hectare rather than on the 1 000-grain weight. A set of improved management practices(IP) for maize production was designed by employing a boundary line(BL) approach and tested on farms. Results showed that the IP could increase yield by 18.4% and PFPN by 31.1%, compared with traditional farmer practices(FP), and reduce the nitrogen(N) surplus by 57.9 kg ha^–1. However,in terms of IP effect, there was a large heterogeneity among different smallholder farmers’ fields, meaning that, precise technologies were needed in different sites especially for N fertilizer management. Our results are valuable for policymakers and smallholder farmers for meeting the objectives of green development in agricultural production.